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Parse command-line arguments: Difference between revisions
Add implementation in Standard ML (SML/NJ and MLton)
(Add implementation in Standard ML (SML/NJ and MLton)) |
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println(s"Received the following arguments: + ${args.mkString("", ", ", ".")}")
}</lang>
=={{header|Standard ML}}==
{{works with|SML/NJ}}
{{works with|MLton}}
The following code listing can be compiled with both [[SML/NJ]] and [[MLton]]:
<lang sml>structure Test = struct
exception FatalError of string
fun main (prog, args) =
(let
exception Args
val switch = ref false
fun do_A arg = print ("Argument of -A is " ^ arg ^ "\n")
fun do_B () = if !switch then print "switch is on\n" else print "switch is off\n"
fun usage () = print ("Usage: " ^ prog ^ " [-help] [-switch] [-A Argument] [-B]\n")
fun parseArgs nil = ()
| parseArgs ("-help" :: ts) = (usage(); parseArgs ts)
| parseArgs ("-switch" :: ts) = (switch := true; parseArgs ts)
| parseArgs ("-A" :: arg :: ts) = (do_A arg; parseArgs ts)
| parseArgs ("-B" :: ts) = (do_B(); parseArgs ts)
| parseArgs _ = (usage(); raise Args)
in
parseArgs args handle Args => raise FatalError "Error parsing args. Use the -help option.";
(* Do something; *)
OS.Process.success
end)
handle FatalError e => (print ("Fatal Error:\n"^e^"\n"); OS.Process.failure)
end
(* MLton *)
val _ = Test.main (CommandLine.name(), CommandLine.arguments())</lang>
=== SML/NJ ===
[[SML/NJ]] can compile source code to a "heap file", witch can than be executed by the interpreter with arguments given (see [http://stackoverflow.com/questions/5053149/sml-nj-how-to-compile-standalone-executable this entry on stackowerflow.com] for more information).
The <code>source.cm</code> file should lock like this:
<lang>Group
is
SOURCE_FILE.sml
$/basis.cm</lang>
To compile the program, use <code>ml-build sources.cm</code>. This should create a "heap file" <code>sources.x86-linux</code>, depending on your architecture.
The heap file can be executed with <code>sml @SMLload=sources.x86-linux ARGUMENTS</code>, or the script [http://www.smlnj.org/doc/heap2exec/index.html <code>heap2exec</code>] can be used to make a single executable.
=== MLton ===
[[MLton]] compiles the source file directly to a executable by invoking <code>mlton SOURCE_FILE.sml</code>.
=={{header|Tcl}}==
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